KR20220088433A - Systems and methods for evaluating junctions - Google Patents

Abstract

A system for evaluating a junction includes first and second electrodes. A layer of dielectric material is positioned at least partially between the first electrode and the second electrode. A power source is connected to the first and second electrodes. The power source is configured such that the first and second electrodes generate an electric arc. The electric arc is configured to at least partially remove the sacrificial material layer to create a plasma.

Description

Systems and methods for evaluating junctions

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Patent Application No. 16/670,857, filed on October 31, 2019, which is incorporated herein by reference in its entirety.

field of initiation

The present disclosure relates to systems and methods for evaluating a bond between two components. More specifically, the present disclosure relates to systems and methods for evaluating adhesive bonding between two components using a plasma actuator.

Laser bond inspection (LBI) is a process used to evaluate adhesive bonding of bonded structures. LBI uses laser pulses to create a plasma that generates stress waves in the bonded structure. In one example, the bonded structure comprises carbon fiber reinforced polymer (CFRP) to CFRP or CFRP to metal. The stress wave mechanically creates a tensile load in the adhesive bond. During exposure to this load, weak joints will fail and strong joints will not. Thus, bonded structures with weak joints are identified and either repaired or discarded. However, current LBI systems are large and expensive. Accordingly, there is a need for improved systems and methods for evaluating junctions.

A system for evaluating junctions is disclosed. The system includes a first electrode and a second electrode. A dielectric material layer is positioned at least partially between the first electrode and the second electrode. A power source is connected to the first and second electrodes. The power source is configured such that the first and second electrodes generate an electric arc. The electric arc is configured to at least partially remove the sacrificial material layer to create a plasma.

In another embodiment, the system includes a support. The system also includes a first electrode in contact with the support. The system also includes a second electrode spaced apart from the support and the first electrode. The system also includes a layer of dielectric material in contact with the support. The dielectric material layer is positioned at least partially between the support and the second electrode and at least partially between the first electrode and the second electrode such that the second electrode does not contact the support or the first electrode. The system also includes a power source coupled to the first and second electrodes. The power source is configured to transmit alternating current pulses to the first and second electrodes causing the first and second electrodes to generate an electric arc. The electric arc at least partially removes the layer of sacrificial material on the bonded structure to create a plasma. The generation of the plasma generates a compressed wave that propagates into the bonded structure. The compression wave is reflected as a tension wave at the junction of the bonded structure.

Methods for evaluating junctions are also disclosed. The method includes disposing a layer of sacrificial material on the surface of the bonded structure. The method also includes sending electrical pulses to the first and second electrodes that cause the first and second electrodes to generate an electric arc. The electric arc at least partially removes the layer of sacrificial material to create a plasma. The generation of the plasma generates a compressed wave that propagates into the bonded structure. The compression wave is reflected as a tension wave at the junction of the bonded structure.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and descriptive only and do not limit the present teachings as claimed.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate aspects of the present teachings and together with the description serve to explain the principles of the present teachings.
1 shows a schematic diagram of a system for evaluating bonding in a bonded structure according to an embodiment.
2 shows a flow diagram of a method for evaluating bonding in a bonded structure according to an embodiment.
It should be noted that some details in the drawings are shown simplified for ease of understanding rather than maintaining strict structural accuracy, detail, and scale.

Reference will now be made in detail to the present teachings, examples of which are shown in the accompanying drawings. In the drawings, like reference numbers are used throughout to designate like elements. DETAILED DESCRIPTION In the following description, reference is made to the accompanying drawings, which form a part hereof and which illustrate by way of illustration specific examples of carrying out the present teachings. Accordingly, the following description is merely an example.

The present disclosure relates to plasma actuators that represent a smaller and less expensive alternative to LBI systems. The plasma actuator includes a support, one or more electrodes, and a layer of dielectric material. The plasma actuator is configured to generate an electric arc that at least partially removes the layer of sacrificial material to create a plasma, which waves propagating into the bonded structure to assess the quality of the bonding as described in more detail below. causes

1 shows a schematic diagram of a system 100 for evaluating bonding in a bonding structure 110 according to one embodiment. System 100 includes a plasma actuator that provides an alternative to an LBI system. Accordingly, the system 100 evaluates (eg, assists in determining the quality of the bond) in the bonding structure 110 without the use of a laser. The evaluation of bonding can be performed according to ASTM STP1455 - Mechanism of Adhesion in Secondary Bonding of Fiberglass Composites and Peel Ply Surface Formulations. More specifically, system 100 applies a predetermined force to the bond. The predetermined force may be between about 30% and about 70% (eg, about 50%) of the force required to break the ideal joint (or between 30% and 70% (eg, about 50%) of the force required to break the ideal joint. 50%)). Then the junction is inspected. If the joint fails or fails, the joint is passed or satisfactory. If the joint is broken or destroyed, the joint does not pass or is unsatisfactory.

The bonding structure 110 includes a first component 112 and a second component 114 that are bonded together by a bonding material 116 (eg, a bond). As can be appreciated, there may be more components joined together, but only two components are shown for simplicity. In some examples, first and second components 112 , 114 are at least partially made of CFRP. In another example, first component 112 is at least partially made of CFRP and second component 114 is at least partially made of metal. The bonding material 116 may be a resin, an adhesive, or an epoxy (eg, boron epoxy or carbon epoxy).

The system 100 includes a support 120 . Support 120 may also be referred to as a support surface or substrate. Support 120 may be or include a polyimide material, a polyamide material, or both. In some examples, support 120 is at least in part KAPTON® It is made of polyamide tape like tape. Support 120 provides high heat resistance and high dielectric strength. Support 120 also prevents unintended dielectric arcing.

System 100 also includes one or more electrodes (two shown: first electrode 130A and second electrode 130B). The first and second electrodes 130A, 130B are configured to generate an electric arc as described in more detail below.

The first and second electrodes 130A, 130B are at least partially made of copper or other metal. The electric arc depends, at least in part, on the material(s) of the first and second electrodes 130A, 130B. For example, the material(s) may affect the size, direction and/or temperature of the electric arc.

In some embodiments, first and second electrodes 130A, 130B are the same size (eg, length, width, and/or height). However, in some embodiments, such as those shown in FIG. 1 , the first electrode 130A has a different size (eg, a different length) than the second electrode 130B. For example, the first electrode 130A may have a length of about 10 mm to about 30 mm, such as about 20 mm (or 10 mm to 30 mm, such as 20 mm), and the second electrode ( 130B) may have a length of about 1 mm to about 10 mm, such as about 5 mm (or 1 mm to 10 mm, such as 5 mm). The electric arc depends, at least in part, on the size (eg, length) of the first and second electrodes 130A, 130B. The size (eg, length) affects the size, direction and/or temperature of the electric arc. As the size of the electrodes 130A and 130B increases, the amount of current required to generate an electric arc also increases. The larger the electric arc, the higher the temperature.

The first and second electrodes 130A and 130B are spaced apart from each other. As shown, the first and second electrodes 130A, 130B may be spaced apart from each other by a first distance 132 in a first direction parallel or substantially parallel to the surface 118 of the junction structure 110 . . The first and second electrodes 130A, 130B may also be spaced apart from each other by a second distance 134 in a second direction perpendicular or substantially perpendicular to the surface 118 of the bonding structure 110 . The first distance 132 is between about 2 mm and 10 mm, such as about 5 mm (or between 2 mm and 10 mm, such as 5 mm), and the second distance 134 is between about 0.5 mm and about 2 mm. , for example about 1 mm (or 0.5 mm to 2 mm, for example 1 mm). Accordingly, as shown, the first electrode 130A is located further away from the junction structure 110 than the second electrode 130B. The electric arc depends, at least in part, on the spacing/position of the first and second electrodes 130A, 130B with respect to each other. For example, the spacing/position affects the size, direction and/or temperature of the electric arc. Moving the first and second electrodes 130A, 130B closer together reduces the size of the electric arc, which reduces the temperature of the electric arc. Conversely, moving the first and second electrodes 130A, 130B further increases the size of the electric arc, which increases the temperature of the electric arc.

System 100 also includes a layer of dielectric material 140 positioned at least in part between first and second electrodes 130A, 130B. The first direction (see above) may be parallel or substantially parallel to the plane 142 through the dielectric material layer 140 , and the second direction may be perpendicular or substantially perpendicular to the plane 142 . The plane 142 may also be parallel or substantially parallel to the surface 118 of the bonding structure 110 . The dielectric material layer 140 may have a thickness of about 0.5 mm to about 3 mm, such as about 1 mm (or 0.5 mm to 3 mm, such as 1 mm). The dielectric material layer 140 may be or include a polyimide film with a silicone adhesive such as KAPTON® tape. In another embodiment, the dielectric material layer 140 is at least partially made of polytetrafluoroethylene (PTFE). For example, the dielectric material layer 140 may be made of TEFLON®. The dielectric material layer 140 is configured to provide an electrical barrier between the first electrode 130A and the second electrode 130B. As the thickness and/or resistance of the dielectric barrier increases, more current is required to generate an electric arc. Conversely, as the thickness and/or resistance of the dielectric barrier decreases, less current is required to generate an electric arc.

As shown, the first electrode 130A is in contact with and/or coupled to the support 120 and/or the dielectric material layer 140 . The second electrode 130B is in contact with and/or coupled to the dielectric material layer 140 , but the dielectric material layer 140 is the support 120 , the first electrode 130A, the second electrode 130B, or a combination thereof. contacted and/or combined with the combination.

System 100 includes a power source 150 coupled to first and second electrodes 130A, 130B. The power source 150 may have a voltage of about 40 kV (kilovolt, kilovolt) to about 60 kV (or 40 kV to 60 kV). The power supply 150 may be from about 10 ns (nanoseconds) to about 1 ms (milliseconds), from about 25 ns to about 500 ns, or from about 50 ns to about 200 ns (or from 10 ns to 1 ms, 25 ns). to 500 ns or 50 ns to 200 ns). For example, a pulse may have a duration of 100 ns or about 100 ns. The pulse causes the first and second electrodes 130A, 130B to generate an electric arc.

The sacrificial material layer 160 bonds to and/or contacts the surface 118 of the bonding structure 110 . The sacrificial material layer 160 is made of a material configured to be at least partially removed by an electric arc to create a plasma. For example, the sacrificial material layer 160 may be made, at least in part, of polyvinyl chloride tape.

A liquid (eg, water or FLUORINERT®) 170 is positioned at least partially between the surface 118 of the bonding structure 110 and the dielectric material layer 140 . As shown, a liquid 170 is located on the sacrificial material layer 160 . As described in greater detail below, removal of the sacrificial material layer 160 generates a compressive wave, and the liquid 170 directs at least a portion of the compressive wave into the bonding structure 110 (eg, the bonding material 116 ). ) to) proceed.

2 shows a flow diagram of a method 200 for evaluating bonding in bonding structure 110 according to one embodiment. The method 200 may be performed using the system 100 . Although an exemplary order of method 200 is described below, it will be understood that one or more steps of method 200 may be performed in a different order and/or may be omitted.

The method 200 includes disposing a sacrificial material layer 160 on the surface 118 of the bonding structure 110 as at 202 . In some examples, the sacrificial material layer 160 is attached to the surface 118 . Method 200 also includes placing liquid 170 between system 100 and sacrificial material layer 160 as at 204 . In some examples, a liquid is located on the sacrificial material layer 160 .

Method 200 includes generating electrical pulses using system 100 as at 206 . More specifically, the power source 150 is connected to the electrodes 130A, 130B to apply an electrical (eg, AC) pulse to the electrodes 130A and 130B to cause the electrodes 130A and 130B to generate an electric arc. send. The electric arc at least partially removes at least a portion of the sacrificial material layer 160 to create a plasma 180 (see FIG. 1 ). Thus, the plasma 180 can be generated without the user of a laser, which allows the system 100 to have a smaller footprint and to be less expensive than conventional LBI systems.

A first wave is generated in response to removal of the sacrificial material layer 160 and/or generation of the plasma 180 . The first wave is a compression wave. The first wave may be propagated towards the surface 118 of the bonding structure 110 (eg, towards the bonding material 116 ), at least in part, by the liquid 170 . The first wave may also or instead be at least partially dependent on the material of the electrodes 130A, 130B, the size of the electrodes 130A, 130B, the location of the electrodes 130A, 130B, the location of the dielectric material layer 140, or a combination thereof. may proceed toward the surface 118 of the bonding structure 110 (eg, towards the bonding material 116 ). The first wave is reflected from the junction structure 110 . More specifically, the first wave is reflected as a second wave at the bonding material 116 and/or the surface 118 . The second wave is a tension wave.

The first wave and/or the second wave may apply a predetermined force to the bond (eg, the bonding material 116 ). The predetermined force is between about 30% and about 70%, such as about 50% (or between 30% and 70%, such as 50%) of the force required to break the ideal bond.

Method 200 also includes examining bonding structure 110 as at 208 . For example, the bonding (eg, bonding material 116 ) may be subjected to a non-destructive testing (eg, an ultrasound imaging system or an ultrasound inspection system) after a first wave is reflected off the bonding material 116 to form a second wave. may be inspected with a destructive inspection, NDI) system 190 (see FIG. 1 ). The inspection detects mismatches and/or damage to the junction that occurs in response to contact with the first wave and/or the second wave. If the inspection reveals that the bond (eg, the bonding material 116 ) is broken or destroyed, the quality of the bond is determined to be poor (ie, the bond does not pass the inspection). If the inspection reveals that the bond (eg, the bonding material 116 ) is unbroken or unbroken, then the quality of the bond is determined to be good (ie, the bond passes the inspection). Inspection of these bonds is a requirement of ASTM D5528-13 - Standard Test Method for Mode 1 Interlaminar Fracture Toughness of Unidirectional Fiber-reinforced Polymer matrix composites. is sufficient to satisfy Alternative or additional steps may also be performed.

In other embodiments, one or more portions of system 100 may be replaced or modified to generate different pulse widths, electric arcs with different characteristics, waves with different characteristics, or combinations thereof. For example, one or both of electrodes 130A, 130B may be replaced with other electrodes made of other materials and/or having other sizes/shapes. Also, the arrangement of the electrodes 130A and 130B (eg, the spacing between the electrodes 130A and 130B) may be changed. In other examples, the dielectric material layer 140 may be replaced with another dielectric material layer made of a different material and/or having a different shape/size. Also, the arrangement of the dielectric material layer 140 may be changed. Replacing or modifying electrodes 130A, 130B and/or dielectric material layer 140 as described above affects the size, direction, and/or temperature of the electric arc. For example, the dielectric material layer 140 may be replaced with a second dielectric material layer having a different thickness and/or resistance that affects the amount of current required to generate the electric arc and/or the temperature of the electric arc. .

In at least one embodiment, the system 100 may not include/without inspection tape having copper traces, as often used by LBI systems, which may cause the system 100 to perform compressive and/or tensile waves. Because it does not include an electromagnetic transducer (EMAT) for converting In practice the system does not receive compressed waves.

The system 100 and method 200 described above may replace the peel ply test in which a mechanically applied stress is used to release a bond. The system 100 and method 200 described above may also replace LBI testing using a laser to generate plasma and compressed waves.

The tensile force required to damage or break the bond with satisfactory quality/passing quality may be known prior to performing method 200 . Thus, the wave generated during the test may have a force (eg, 50% to 70% of the force, or about 50% to about 70% of the force) that is less than the force required to break the bond. If the inspection shows that the joint is still intact after the wave has made contact with it, the joint is considered to have the desired quality (the joint passes the test). If the inspection reveals that the joint is damaged or broken after the wave has made contact with it, the joint is considered not of the desired quality (the joint fails the test).

In addition, the present disclosure includes examples according to the following clauses:

Clause 1. A system for evaluating a junction, comprising: a first electrode; a second electrode; a layer of dielectric material located at least partially between the first electrode and the second electrode; and a power source coupled to the first and second electrodes, the power source configured to cause the first and second electrodes to generate an electric arc, the electric arc configured to at least partially remove the sacrificial material layer to create a plasma do.

Clause 2. The system of clause 1, wherein the first electrode, the second electrode, or both are made of copper.

Clause 3. The system of any one of clauses 1,2, wherein the first electrode is spaced apart from the second electrode by a first distance in a first direction, wherein the first distance is between 0.5 mm and 2 mm or between about 0.5 mm and about 2 mm, and the first direction is parallel or substantially parallel to the plane through the dielectric material layer.

Clause 4. The system of any one of clauses 1-3, wherein the first electrode is spaced apart from the second electrode by a second distance in a second direction, wherein the second distance is between about 2 mm and about 10 mm or between 2 mm and 10 mm, and the second direction is perpendicular or substantially perpendicular to the plane through the dielectric material layer.

Clause 5. The system of any of clauses 1-4, wherein the first electrode is located further from the sacrificial material layer than the second electrode.

Clause 6. The system of any of clauses 1-5, wherein the first electrode has a different size than the second electrode.

Clause 7. The system of any of clauses 1-6, wherein the first electrode is longer in a first direction than the second electrode, the first direction being parallel or substantially parallel to a plane through the dielectric material layer.

Clause 8. The system of any one of clauses 1-7, wherein the power source is configured to send an alternating current pulse having a duration of between 50 ns and 200 ns or between about 50 ns and about 200 ns to the first and second electrodes; The alternating pulse causes the first and second electrodes to generate an electric arc.

Clause 9. The system of any one of clauses 1-8, further comprising a support made of a polyimide material, a polyamide material, or both, wherein the first electrode is in contact with the support and the dielectric material layer is in contact with the support; The second electrode does not contact the support.

Clause 10. The system of any one of clauses 1-9, wherein the plasma is generated at least partially between the dielectric material layer and the sacrificial material layer.

Clause 11. A system for evaluating a joint comprising: a support; a first electrode in contact with the support; a second electrode spaced apart from the support and the first electrode; a layer of dielectric material in contact with the support; and a power source coupled to the first and second electrodes, wherein the dielectric material layer is at least partially between the support and the second electrode and at least partially between the first electrode and the second electrode such that the second electrode does not contact the support or the first electrode. disposed between the electrodes, the power source being configured to transmit alternating pulses to the first and second electrodes causing the first and second electrodes to generate an electric arc, the electric arc being at least a sacrificial force on the junction structure to create a plasma Partially removing the material layer, the generation of the plasma generates a compression wave that propagates to the junction structure, which is reflected as a tension wave at the junction of the junction structure.

Clause 12. The system of clause 11, wherein the first electrode is spaced apart from the second electrode by a first distance in a first direction, wherein the first distance is between about 0.5 mm and about 2 mm or between 0.5 mm and 2 mm, and The direction is parallel or substantially parallel to the plane through the dielectric material layer, the first electrode being spaced apart from the second electrode by a second distance in a second direction, the second distance being about 2 mm to about 10 mm or 2 mm to 10 mm, the second direction is perpendicular or substantially perpendicular to the plane through the dielectric material layer, the first electrode positioned further from the sacrificial material layer than the second electrode.

Clause 13. The system of any one of clauses 11, 12, wherein the first electrode has a length of between about 10 mm and about 20 mm or between about 10 mm and 20 mm in the first direction and the second electrode has a length of between about 10 mm and about 20 mm in the first direction. 1 mm to about 10 mm or 1 mm to 10 mm in length.

Clause 14. The system of any one of clauses 11-13, wherein water is positioned between the dielectric material layer and the sacrificial material layer, and the water propagates a portion of the compressive wave toward the junction of the junction structure.

Clause 15. The system of any one of clauses 11-14, wherein the system is capable of generating the plasma and compressed wave without using a laser.

Clause 16. A method for evaluating bonding, comprising: disposing a layer of sacrificial material on a surface of a bonding structure; and transmitting electrical pulses to the first and second electrodes to cause the first and second electrodes to generate an electric arc, wherein the electric arc at least partially removes the layer of sacrificial material to create a plasma. and generation of the plasma generates a compression wave that travels to the junction structure, and the compression wave is reflected as a tension wave at the junction of the junction structure.

Clause 17. The method of clause 16, further comprising placing a liquid proximate to the sacrificial material layer, the liquid propagating at least a portion of the compression wave into the bonding structure.

Clause 18. The method of clause 17, wherein the dielectric material layer is positioned at least partially between the first electrode and the second electrode, and the liquid and plasma are positioned between the sacrificial material layer and the dielectric material layer.

Clause 19. The method of any one of clauses 16-18, further comprising inspecting the junction using an ultrasound imaging system after the compressed wave is reflected off the junction.

Clause 20. The method of any one of clauses 16-19, wherein the first electrode is spaced apart from the second electrode by a first distance in a first direction, wherein the first distance is between about 0.5 mm and about 2 mm or between 0.5 mm and 2 mm, the first direction parallel or substantially parallel to a plane through the dielectric material layer, the first electrode being spaced apart from the second electrode by a second distance in a second direction, the second distance being about 2 mm to about 10 mm or 2 mm to 10 mm, the second direction being perpendicular or substantially perpendicular to the plane through the dielectric material layer, the first electrode positioned further from the sacrificial material layer than the second electrode.

Clause 21. A system for evaluating a junction, comprising: a first electrode; a second electrode; a layer of dielectric material located at least partially between the first electrode and the second electrode; and a power source coupled to the first and second electrodes, wherein the power source is configured to provide current to the first and second electrodes to cause the first and second electrodes to generate an electric arc, the electric arc generating a plasma to at least partially remove the sacrificial material layer.

Clause 22. The system of clause 21, wherein the first electrode and/or the second electrode are made of copper.

Clause 23. The system of clauses 21 or 22, wherein the first electrode is spaced apart from the second electrode by a first distance in a first direction, wherein the first distance is between 0.5 mm and 2 mm or between about 0.5 mm and about 2 mm; The first direction is parallel or substantially parallel to the plane through the dielectric material layer.

Clause 24. The system of clause 23, wherein the first electrode is spaced apart from the second electrode by a second distance in a second direction, wherein the second distance is between about 2 mm and about 10 mm or between 2 mm and 10 mm; The direction is perpendicular or substantially perpendicular to the plane through the dielectric material layer.

Clause 25. The system of clause 24, wherein the first electrode is positioned further from the sacrificial material layer than the second electrode.

Clause 26. The system of any one of clauses 21-25, wherein the first electrode has a different size than the second electrode.

Clause 27. The system of any one of clauses 21-26, wherein the first electrode is longer than the second electrode in a first direction, the first direction parallel or substantially parallel to a plane through the dielectric material layer.

Clause 28. The system of any one of clauses 21-27, wherein the power source is configured to supply an alternating current pulse having a duration between 50 ns and 200 ns or between about 50 ns and about 200 ns to the first and second electrodes; The alternating pulse causes the first and second electrodes to generate an electric arc.

Clause 29. The system of any one of clauses 21-28, further comprising a support made of a polyimide material and/or a polyamide material, wherein the first electrode is in contact with the support and the layer of dielectric material is in contact with the support; The second electrode is spaced apart from the support.

Clause 30. The system of any one of clauses 21-29, wherein the plasma is generated at least partially between the dielectric material layer and the sacrificial material layer.

Clause 31. The system of any one of clauses 21-30, wherein the system is suitable for evaluating a bonding of a bonding structure, eg, a CFRP to CFRP or a CFRP to metal bonding structure.

Clause 32. The system of clause 31, further comprising a bonding structure, eg, a CFRP to CFRP or a CFRP to metal bonding structure.

Clause 33. A system for evaluating a joint comprising: a support; a first electrode in contact with the support; a second electrode spaced apart from the support and the first electrode; a layer of dielectric material in contact with the support; and a power source coupled to the first and second electrodes, wherein the dielectric material layer is at least partially between the support and the second electrode and at least partially between the first electrode and the second electrode such that the second electrode is spaced apart from the support and the first electrode. disposed between the electrodes, the power source being configured to transmit alternating pulses to the first and second electrodes causing the first and second electrodes to generate an electric arc, the electric arc being at least a sacrificial force on the junction structure to create a plasma Partially removing the material layer, the generation of the plasma generates a compression wave that propagates to the junction structure, which is reflected as a tension wave at the junction of the junction structure.

Clause 34. The system of clause 33, wherein the first electrode is spaced apart from the second electrode by a first distance in a first direction, wherein the first distance is between about 0.5 mm and about 2 mm or between 0.5 mm and 2 mm, and the direction is parallel or substantially parallel to the plane through the dielectric material layer; and/or the first electrode is spaced apart from the second electrode by a second distance in a second direction, wherein the second distance is between about 2 mm and about 10 mm or between 2 mm and 10 mm, and wherein the second direction is planar through the dielectric material layer. perpendicular or substantially perpendicular to, the first electrode positioned further from the sacrificial material layer than the second electrode.

Clause 35. The system of clause 34, wherein the first electrode has a length of from about 10 mm to about 20 mm or from 10 mm to 20 mm in the first direction and the second electrode is from about 1 mm to about 10 mm in the first direction. mm or a length of 1 mm to 10 mm.

Clause 36. The system of clause 35, wherein water is positioned between the dielectric material layer and the sacrificial material layer to propagate a portion of the compressive wave toward the bonding of the bonding structure.

Clause 37. The system of clause 36, wherein the system is capable of generating the plasma and compressed wave without using a laser.

Clause 38. The system of any one of clauses 33-37, wherein the system is suitable for evaluating a bonding of a bonding structure, eg, a CFRP to CFRP or a CFRP to metal bonding structure.

Clause 39. The system of clause 38, further comprising a bonding structure, eg, a CFRP to CFRP or CFRP to metal bonding structure.

Clause 40. A method for evaluating bonding, comprising: disposing a layer of sacrificial material on a surface of a bonding structure; and transmitting electrical pulses to the first and second electrodes to cause the first and second electrodes to generate an electric arc, wherein the electric arc at least partially removes the layer of sacrificial material to create a plasma. and generation of the plasma generates a compression wave that travels to the junction structure, and the compression wave is reflected as a tension wave at the junction of the junction structure.

Clause 41. The method of clause 40, further comprising positioning a liquid proximate to the sacrificial material layer, the liquid propagating at least a portion of the compression wave into the bonding structure.

Clause 42. The method of clause 41, wherein a layer of dielectric material is positioned at least partially between the first electrode and the second electrode, and the liquid and plasma are positioned between the layer of sacrificial material and the layer of dielectric material.

Clause 43. The method of any one of clauses 40-42, further comprising inspecting the junction using an ultrasound imaging system after the compressed wave is reflected off the junction.

Clause 44. The method of any one of clauses 40-43, wherein the first electrode is spaced apart from the second electrode by a first distance in a first direction, wherein the first distance is between about 0.5 mm and about 2 mm or between 0.5 mm and 2 mm, the first direction parallel or substantially parallel to a plane through the dielectric material layer, the first electrode being spaced apart from the second electrode by a second distance in a second direction, the second distance being about 2 mm to about 10 mm or 2 mm to 10 mm, the second direction being perpendicular or substantially perpendicular to the plane through the dielectric material layer, the first electrode positioned further from the sacrificial material layer than the second electrode.

Clause 45. The method of any one of clauses 40-44, wherein the junction structure is a CFRP to CFRP or a CFRP to metal junction structure.

Clause 46. A method for evaluating bonding using the system of any one of clauses 1-39, comprising: disposing a layer of sacrificial material on a surface of a bonding structure; and transmitting electrical pulses to the first and second electrodes to cause the first and second electrodes to generate an electric arc, wherein the electric arc at least partially removes the layer of sacrificial material to create a plasma; , the generation of the plasma generates a compression wave that propagates to the junction structure, and the compression wave is reflected as a tension wave at the junction of the junction structure.

Clause 47. The method of clause 46, further comprising disposing a liquid proximate to the layer of sacrificial material to propagate at least a portion of the compression wave into the bonding structure.

Clause 48. The method of clauses 46 or 47, further comprising inspecting the junction using an ultrasound imaging system after the compressed wave is reflected off the junction.

Notwithstanding that the numerical ranges and parameters defining the broad scope of the present disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. All figures, however, inherently contain certain errors due to standard deviations found in their respective test measurements. Moreover, all ranges disclosed herein are to be understood to include any and all subranges subsumed therein.

While the present teachings have been illustrated in connection with one or more embodiments, changes and/or modifications may be made to the illustrated examples without departing from the spirit and scope of the appended claims. Further, although particular features of the present teachings may be disclosed for only one of several embodiments, such features may be combined with one or more other features of other embodiments that may be desirable and advantageous for any given or particular function. As used herein, the terms “a”, “an” and “the” may refer to one or more components or portions of components. As used herein, the terms “first” and “second” may refer to two different components or portions of components. As used herein, the term "at least one of A and B" in reference to a list of items such as A and B means A alone, B alone, or A and B. Those skilled in the art will recognize that these and other variations are possible. Also, to the extent that the terms “comprising”, “comprises”, “having”, “having”, “having” or variations thereof are used in the specification and claims, these terms are intended to include: These terms are intended to be included in a manner analogous to the term "comprising". Moreover, in the discussion and claims herein, the term "about" indicates that the recited values may be varied slightly unless the recited values result in unsuitability of process or structure for the intended purpose described herein. Finally, “yes” indicates that the description is used by way of illustration and not meant to be ideal.

It will be understood that variations or substitutions of the other features and functions disclosed above may be incorporated into many other systems or applications. Various substitutions, modifications, variations or improvements, which are intended to be encompassed by the following claims, but are not presently foreseen or anticipated, may subsequently occur by those skilled in the art.

Claims (20)

A system for evaluating junctions, comprising:
a first electrode;
a second electrode;
a layer of dielectric material positioned at least partially between the first electrode and the second electrode; and
Provided with a power source connected to the first and second electrodes,
wherein the power source is configured to cause the first and second electrodes to generate an electric arc, wherein the electric arc is configured to at least partially remove the sacrificial material layer to create a plasma.
The system of claim 1 , wherein the first electrode, the second electrode, or both are made of copper.
The first electrode of claim 1 , wherein the first electrode is spaced apart from the second electrode by a first distance in a first direction, the first distance being between about 0.5 mm and about 2 mm, the first direction being parallel to a plane through the dielectric material layer or A system characterized in that it is substantially parallel.
The method of claim 1 , wherein the first electrode is spaced apart from the second electrode by a second distance in a second direction, the second distance being from about 2 mm to about 10 mm, the second direction being perpendicular to the plane through the dielectric material layer or A system characterized in that it is substantially vertical.
The system of claim 1 , wherein the first electrode is located further away from the sacrificial material layer than the second electrode.
The system of claim 1 , wherein the first electrode has a different size than the second electrode.
The system of claim 1 , wherein the first electrode is longer in a first direction than the second electrode, the first direction parallel or substantially parallel to a plane through the dielectric material layer.
8. The power source of any one of claims 1 to 7, wherein the power source is configured to transmit alternating current pulses having a duration between about 50 ns and about 200 ns to the first and second electrodes, the alternating pulses comprising the first and second electrodes. A system characterized in that the two electrodes are configured to generate an electric arc.
The support according to claim 1, further comprising a support made of polyimide material, polyamide material, or both, wherein the first electrode is in contact with the support, the layer of dielectric material is in contact with the support, and the second electrode is not in contact with the support. A system characterized in that.
The system of claim 1 , wherein the plasma is generated at least partially between the dielectric material layer and the sacrificial material layer.
A system for evaluating junctions, comprising:
support fixture;
a first electrode in contact with the support;
a second electrode spaced apart from the support and the first electrode;
a layer of dielectric material in contact with the support; and
Provided with a power source connected to the first and second electrodes,
the dielectric material layer is disposed at least partially between the support and the second electrode and at least partially between the first electrode and the second electrode such that the second electrode does not contact the support or the first electrode;
The power source is configured to transmit alternating pulses to the first and second electrodes that cause the first and second electrodes to generate an electric arc, the electric arc at least partially removing the layer of sacrificial material on the junction structure to create a plasma. and the generation of the plasma generates a compression wave propagating to the junction structure, and the compression wave is reflected as a tension wave at the junction of the junction structure.
12. The method of claim 11, wherein the first electrode is spaced apart from the second electrode by a first distance in a first direction, the first distance being from about 0.5 mm to about 2 mm, the first direction being parallel to a plane through the dielectric material layer or substantially parallel,
The first electrodes are spaced apart a second distance in a second direction, the second distance being from about 2 mm to about 10 mm, the second direction being perpendicular or substantially perpendicular to a plane through the layer of dielectric material, the first electrode comprising: The system of claim 1, wherein the two electrodes are located further away from the layer of sacrificial material.
13. The system of claim 12, wherein the first electrode has a length of about 10 mm to about 20 mm in the first direction and the second electrode has a length of about 1 mm to about 10 mm in the first direction. .
12. The system of claim 11, wherein water is disposed between the layer of dielectric material and the layer of sacrificial material, wherein the water propagates a portion of the compression wave toward the junction of the junction structure.
15. The system according to any one of claims 11 to 14, wherein the system is capable of generating plasma and compressed waves without the use of a laser.
A method for evaluating conjugation comprising:
disposing a sacrificial material layer on the surface of the bonding structure; and
sending electrical pulses to the first and second electrodes to cause the first and second electrodes to generate an electric arc;
wherein the electric arc at least partially removes the layer of sacrificial material to create a plasma, wherein the generation of the plasma generates a compressive wave that propagates to the junction structure, the compressive wave being reflected as a tension wave at the junction of the junction structure. .
17. The method of claim 16, further comprising placing a liquid proximate to the sacrificial material layer, wherein the liquid propagates at least a portion of the compression wave into the bonding structure.
18. The method of claim 17, wherein the dielectric material layer is positioned at least partially between the first and second electrodes, and the liquid and plasma are positioned between the sacrificial material layer and the dielectric material layer.
17. The method of claim 16, further comprising: inspecting the junction using an ultrasound imaging system after the compressed wave is reflected off the junction.
17. The method of claim 16, wherein the first electrode is spaced apart from the second electrode by a first distance in a first direction, wherein the first distance is between about 0.5 mm and about 2 mm, wherein the first direction is parallel to a plane through the dielectric material layer or substantially parallel, wherein the first electrode is spaced apart from the second electrode by a second distance in a second direction, wherein the second distance is between about 2 mm and about 10 mm, and wherein the second direction is perpendicular to or substantially plane through the dielectric material layer. and wherein the first electrode is positioned further away from the sacrificial material layer than the second electrode.

Images